Spectral clustering for jet physics

Abstract

Abstract We present a new approach to jet definition alternative to clustering methods, such as the anti-kT scheme, that exploit kinematic data directly. Instead the new method uses kinematic information to represent the particles in a multidimensional space, as in spectral clustering. After confirming its Infra-Red (IR) safety, we compare its performance in analysing gg → H125 GeV→ H40 GeVH40 GeV→$$ b\overline{b}b\overline{b} $$ b b ¯ b b ¯ , gg → H500 GeV→ H125 GeVH125 GeV→$$ b\overline{b}b\overline{b} $$ b b ¯ b b ¯ and gg, $$ q\overline{q} $$ q q ¯ →$$ t\overline{t} $$ t t ¯ →$$ b\overline{b}{W}^{+}{W}^{-} $$ b b ¯ W + W − →$$ b\overline{b} jj\mathrm{\ell}{v}_{\mathrm{\ell}} $$ b b ¯ jj ℓ v ℓ events from Monte Carlo (MC) samples, specifically, in reconstructing the relevant final states, to that of the anti-kT algorithm. Finally, we show that the results for spectral clustering are obtained without any change in the parameter settings of the algorithm, unlike the anti-kT case, which requires the cone size to be adjusted to the physics process under study.